A new treatment program has to prove its effectiveness in a randomized controlled trial (RCT). However, health care research trials (HCRT) show that the efficacy of education programs is far less convincing in daily routine. We evaluated whether a new education and treatment program for type 1 diabetic patients (PRIMAS) had similar effects in daily routine as in the RCT 255 people with type 1 diabetes from 42 practices took part in the PRIMAS course and were observed in this HCRT. As in the RCT, PRIMAS consisted of 12 lessons and the outcomes were assessed 6 months after the education course. Primary outcome in both studies was HbA1c assessed in the same central laboratory. Improvement in hypoglycemia Awareness, depressive symptoms, diabetes-related distress, self-efficacy, and diabetes empowerment were secondary outcomes. In order to compare the effects of PRIMAS in the RCT with the effects in the HCRT, effect sizes of differences for each study were contrasted. The difference of the two respective effect sizes (RCT - HCRT) along with the 95% confidence interval was analyzed. HbA1c reduction in the RCT was -0.36% (-3.9 mmol/mol) as compared to -0.39% (-4.3 mmol/mol) in the HCRT. The difference of the effect sizes didn’t exceed the non-inferiority margin of 0.4 (difference of effect size: α -0.03, 95% CI -0.29 to 0.22). Effect sizes in all secondary outcomes were also highly comparable: Improvement of hypoglycemia awareness α 0.11, 95% CI -0.15 to 0.38; reduction of depressive symptoms α -0.08, 95% CI -0.34 to 0.18; reduction of diabetes distress α 0.23, 95% CI -0.04 to 0.49; improvement of self-efficacy α 0.05, 95% CI -0.21 to 0.32; improvement of empowerment α 0.04, 95% CI -0.23 to 0.36. PRIMAS proofed its effi cacy in daily routine and showed similar effect sizes as in the RCT. PRIMAS can contribute to an improvement of routine health care in people with type 1 diabetes.